General Relativity and Quantum Cosmology
The distribution of dark matter (DM) halo around supermassive black holes (BHs) may leave observable imprints on stellar dynamics near galactic centers. Motivated by this, we investigate the orbital motion of the S2 star in the spacetime of…
We investigate timelike geodesics around Damour-Solodukhin wormholes, which are Schwarzschild-like geometries characterized by a deformation parameter $\lambda$ that determines the radius of the throat, $r_{\rm th}$. The radial potential…
In this work, we investigate non-interacting holographic dark energy (HDE) with the Hubble radius as the infrared cutoff in Einstein-Cartan gravity. We derive the Einstein-Cartan equations from the action principle and obtain Friedmann-like…
In a companion paper arXiv:2510.27676, we introduced a non-perturbative classical renormalisation group (RG) flow equation as a novel method for treating strongly interacting problems in general relativity, with a prominent application to…
Static spherically symmetric perfect-fluid solutions of Einstein's equations play a central role in relativistic astrophysics and stellar structure theory. While many exact solutions satisfy Einstein's equations mathematically, only a…
Gravitational waves from merging compact binaries are sensitive to line-of-sight acceleration (LOSA) induced by a massive companion in their vicinity. Interestingly, the leading-order contributions of LOSA and residual orbital eccentricity…
Electron-positron ($e^{+}e^{-}$) pair creation by vacuum breakdown around compact objects is believed to power high-energy astrophysical transients like gamma-ray bursts (GRBs). In this work, we focus on vacuum breakdown around a Kerr black…
This paper utilizes the {\it Black Hole Vision} smartphone application to catalyze a pedagogical shift in General Relativity education through the quantitative analysis of simulated black hole imaging. Presented here for the Schwarzschild…
We study the maximal analytic extension of the Schwarzschild-like black hole solution in Lorentz gauge theory. The lapse function is $f(r)=A_0^{-2}-2\m/r$, so the horizon is located at $r_+=2\m A_0^2$ and the non-affinity coefficient of the…
We provide some guidance and examples to clear up common misconceptions about special relativity. These misconceptions often come from trying to express the truths of special relativity in Newtonian terms rather than in terms more natural…
Close hyperbolic encounters between black holes produce distinctive bursts of gravitational radiation with a time-frequency morphology that is qualitatively different from that of quasi-circular inspirals. Expected to arise in dense stellar…
In this work, we delve into the physics of charged black holes modified by Weyl corrections, a framework that emerges from the subtle non--minimal coupling between spacetime curvature and electromagnetism. We begin by revisiting the…
We investigate the gravitational field of an extended spherically symmetric body within the framework of Extended Relativity (ER), a Lorentz-covariant formulation of relativistic gravity on a Minkowski background. Using a relativistic…
Massive scalar perturbations of asymptotically de Sitter black holes in generalized Proca theory display a sharp interplay between primary hair, horizon structure, and field mass. Using high-order WKB calculations supplemented by…
The gradient expansion and the separate universe approach provide an effective description of inflationary soft modes after coarse-graining shorter-wavelength degrees of freedom. We formulate a locality condition on the quantum state,…
We analytically prove the linear radial stability of non-Abelian black holes with quartic self-interactions. The background, constructed from the Wu--Yang magnetic monopole ansatz, is an exact black-hole solution carrying a non-Abelian…
We construct a new Ricci-flat metric by demagnetizing the recently reported Kerr-Bertotti-Robinson (KBR) solution. The metric is a deformation of the Kerr metric characterized by a parameter $B$, so that the asymptotic Kerr becomes a…
Accurate models of merger remnants are increasingly important for gravitational-wave science, including precision tests of gravity with ringdown, inference of black-hole populations, and modeling hierarchical mergers. For eccentric…
The cosmological gravitational wave background provides a powerful window on parity-violating physics at energies far beyond the reach of terrestrial experiments. However, any colocated planar detector network is insensitive to isotropic…
We show that the quasinormal modes, in the eikonal limit, for accelerating (non-rotating) black holes, are related to the angular velocity of the circular null geodesics and to the corresponding Lyapunov exponent, in the same way as the…